Method of manufacturing silicon optoelectronic device, silicon optoelectronic device manufactured by the method, and image input and/or output apparatus using the silicon optoelectronic device

ABSTRACT

A method of manufacturing a silicon optoelectronic device, a silicon optoelectronic device manufactured by the method, and an image input and/or output apparatus including the silicon optoelectronic device are provided. The method includes preparing an n- or p-type silicon-based substrate, forming a microdefect pattern along a surface of the substrate by etching, forming a control film with an opening on the microdefect pattern, and forming a doping region on the surface of the substrate having the microdefect pattern in such a way that a predetermined dopant of the opposite type to the substrate is injected onto the substrate through the opening of the control film to be doped to a depth so that a photoelectric conversion effect leading to light emission and/or reception by quantum confinement effect in the p-n junction occurs. The silicon optoelectronic device has superior light-emitting efficiency, can be used as at least one of a light-emitting device and a light-receiving device, and has high wavelength selectivity. In addition, the silicon optoelectronic device panel having the two-dimensional array of the silicon optoelectronic devices can be applied in the image input and/or output apparatus capable of directly displaying an image and/or inputting optical information in a screen.

This application claims the priority from Korean Patent Application No.2003-3259, filed on Jan. 17, 2003, in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein in its entiretyby reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of manufacturing a siliconoptoelectronic device, a silicon optoelectronic device manufactured bythe method, and an image input and/or output apparatus having thesilicon optoelectronic device.

2. Description of the Related Art

An advantage of using a silicon semiconductor substrate is that itprovides excellent reliability and allows highly integrated density of alogic device, an operation device, and a drive device on the substrate.Also, a silicon semiconductor material can be used in fabrication of ahighly integrated circuit at much lower cost than a compoundsemiconductor material, due to the use of inexpensive silicon. That iswhy many integrated circuits use silicon as their basic material.

In this regard, studies on fabrication of silicon-based light-emittingdevices have been continued to compatibly use them in fabrication ofintegrated circuits and to obtain inexpensive photoelectronic devices.It has been demonstrated that porous silicon and nano-crystal siliconhave light emission characteristics.

FIG. 1 depicts the section of a porous silicon region formed at a bulkmonocrystalline silicon surface, and an energy band gap between thevalence band and the conduction band of the porous silicon region.

Porous silicon is the result of anodic electrochemical dissolution ofthe surface of bulk monocrystalline silicon, for example, in anelectrolyte solution containing a hydrofluoric acid (HF).

When bulk silicon is subjected to anodic electrochemical dissolution ina HF solution, a porous silicon region 70 having numerous pores 70 a isformed at the surface of the bulk silicon, as shown in FIG. 1. The pores70 a have more Si—H bonds, relative to intact areas 70 b which have notbeen dissolved by a HF solution. The energy band gap between the valenceband energy (Ev) and the conduction band energy (Ec) of the poroussilicon region 70 has a shape contrasting to the porous silicon region70.

Depressions between prominences in energy bands, i.e., the intact areas70 b between the pores 70 a in the porous silicon region 70 exhibits aquantum confinement effect. Therefore, the energy band gap of thedepression becomes larger than that of the bulk silicon, and electronsand holes are trapped in the intact areas 70 b, thereby inducinglight-emitting recombination.

For example, in the porous silicon region 70, when the intact areas 70 bbetween the pores 70 a are formed in the shape of monocrystallinesilicon wires that exhibit a quantum confinement effect, electrons andholes are trapped in the wires, thereby inducing light-emittingrecombination. A light-emitting wavelength can vary from a near-infraredlight area to a blue light area wavelength according to the sizes(widths and lengths) of the wires. In this case, the period of the pores70 a may be about 5 nm and the maximal thickness of the porous siliconregion may be 3 nm, as shown in FIG. 1.

Therefore, when a predetermined voltage is applied to monocrystallinesilicon having the porous silicon region 70 in a porous silicon basedlight-emitting device, light of a predetermined wavelength band can beemitted according to porosity.

However, a porous silicon based light-emitting device as described abovedoes not yet provide reliability as a light-emitting device and exhibitsexternal quantum efficiency (EQE) as low as 0.1%.

FIG. 2 is a schematic sectional view of an example of a nano-crystalsilicon light-emitting device.

Referring to FIG. 2, a nano-crystal silicon light-emitting devicecomprises a stacked structure of a p-type monocrystalline siliconsubstrate 72, an amorphous silicon layer 73 formed on the substrate 72,an insulator 75 formed on the amorphous silicon layer 73, and lower andupper electrodes 76 and 77 formed on the lower surface of the substrate72 and the upper surface of the insulator 75, respectively. Nano-crystalsilicon quantum dots 74 are formed in the amorphous silicon layer 73.

When the amorphous silicon layer 73 is recrystallized by rapid heattreatment at 700° C. under an oxygen atmosphere, the nano-crystalsilicon quantum dots 74 are formed. In this case, the amorphous siliconlayer 73 has a thickness of 3 nm and the nano-crystal silicon quantumdots 74 have a diameter of about 2 to 3 nm.

In a light-emitting device using the nano-crystal silicon quantum dots74 as described above, when a reverse voltage is applied across theupper and lower electrodes 77 and 76, a high electric field is generatedat both ends of the amorphous silicon layer between the siliconsubstrate 72 and the nano-crystal silicon quantum dots 74, therebygenerating electrons and holes of high-energy states. Therefore, thetunneling of the generated electrons and holes into the nano-crystalsilicon quantum dots 74 occurs, thereby resulting in light-emittingrecombination. In this case, a light-emitting wavelength in alight-emitting device using the nano-crystal silicon quantum dots 74decreases as the sizes of the nano-crystal silicon quantum dotsdecrease.

However, light-emitting devices using the nano-crystal silicon quantumdots 74 have problems in that it is difficult to control the sizes ofthe nano-crystal silicon quantum dots and to obtain the uniformity ofthe nano-crystal silicon quantum dots, and light-emitting efficiency isvery low.

SUMMARY OF THE INVENTION

The present invention provides a method of manufacturing a siliconoptoelectronic device which has excellent light-emitting efficiency, canbe used as at least one of a light-emitting device and a light-receivingdevice, and has high wavelength selectivity. The present invention alsoprovides a silicon optoelectronic device manufactured by the method andan image input and/or output apparatus used the silicon optoelectronicdevice.

According to an aspect of the present invention, there is provided amethod of manufacturing a silicon optoelectronic device comprising:preparing an n- or p-type silicon-based substrate; forming a microdefectpattern along a surface of the substrate by etching; forming a controlfilm with an opening on the microdefect pattern; and forming a dopingregion on the surface of the substrate having the microdefect pattern insuch a way that a predetermined dopant of the opposite type to thesubstrate is injected onto the substrate through the opening of thecontrol film to be doped to a depth so that a photoelectric conversioneffect leading to light emission and/or reception by quantum confinementeffect in a p-n junction occurs.

Forming the microdefect pattern may comprise: forming a mask layer onthe surface of the substrate; forming openings of a desired size andperiod in the mask layer; etching the surface of the substratecorresponding to the openings of the mask layer to form the microdefectpattern along the surface of the substrate; and removing the mask layer.

Forming the openings of a desired size and period in the mask layer maybe carried out using a single probe or a multi-probe having an array ofa plurality of probes.

The probe may be an atomic force microscopy (AFM) probe.

The control film may be a silicon oxide film to allow the doping regionto be formed to the depth such that a photoelectrical conversion effectby quantum confinement in the p-n junction between the doped region andthe substrate occurs.

The microdefect pattern may have a period corresponding to thewavelength of light emitted and/or received.

The microdefect pattern may be formed to a single period to emit and/orreceive light of a single wavelength.

When the control film is formed with a plurality of openings on themicrodefect pattern and a plurality of doping regions are formed throughthe openings, an array of a plurality of silicon optoelectronic devicesmay be obtained.

When the microdefect pattern is formed to a plurality of microdefectpattern regions having different periods, the control film is formedwith a plurality of openings corresponding to the periods, and aplurality of doping regions are formed through the openings, an array ofa plurality of silicon optoelectronic devices that emit and/or receivelight of a plurality of wavelengths may be obtained.

According to another aspect of the present invention, there is provideda silicon optoelectronic device manufactured by at least one of themethods as described above.

According to yet another aspect of the present invention, there isprovided an image input and/or output apparatus comprising a siliconoptoelectronic device panel having a two-dimensional array of siliconoptoelectronic devices, each of which inputs and/or outputs an image,formed on an n- or p-type silicon-based substrate, each of the siliconoptoelectronic devices comprising: a microdefect pattern formed along asurface of the substrate by etching; and a doping region formed on thesurface of the substrate having the microdefect pattern using apredetermined dopant of the opposite type to the substrate to be dopedto a depth so that a photoelectric conversion effect leading to lightemission and/or reception by quantum confinement effect in a p-njunction occurs.

When both input and output of an image are possible, some of the siliconoptoelectronic devices may input an image and the others of the siliconoptoelectronic devices may output an image.

When both input and output of an image are possible, each of the siliconoptoelectronic devices may input and output an image.

Electrodes may be patterned on the substrate to carry out the inputand/or output of an image from the silicon optoelectronic device panelon a pixel-by-pixel basis.

The silicon optoelectronic device panel may comprise three or more ofthe silicon optoelectronic devices per each pixel.

In this case, the three or more of the silicon optoelectronic devicescorresponding to each pixel may have the microdefect patterns ofdifferent periods and may emit and/or receive light of differentwavelengths to represent a color image.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 depicts the section of a porous silicon region formed at a bulkmonocrystalline silicon surface and an energy band gap between thevalence band and the conduction band of the porous silicon region;

FIG. 2 is a schematic sectional view of an example of a nano-crystalsilicon light-emitting device;

FIGS. 3 through 6 depict processes of manufacturing a siliconoptoelectronic device according to an embodiment of the presentinvention;

FIG. 7 is a schematic view showing a principle of forming an opening ina mask layer using an atomic force microscopy (AFM) probe;

FIGS. 8A and 8B depict various tips used in the AFM probe;

FIG. 9 is a schematic view of patterned openings formed in a mask layerusing an AFM single probe or an AFM multi-probe;

FIG. 10 is a schematic view of a microdefect pattern having triangularprotrusions formed along a surface of a substrate, i.e., a triangularmicrodefect pattern, as viewed in two dimensions;

FIG. 11 is a schematic view of a microdefect pattern having trapezoidalprotrusions formed along a surface of a substrate, as viewed in twodimensions;

FIG. 12 is a schematic sectional view of a silicon optoelectronic deviceaccording to an embodiment of the present invention;

FIG. 13 depicts microdefect patterns having periods T_(R), T_(G), andT_(B) respectively corresponding to a red light wavelength band, a greenlight wavelength band, and a blue light wavelength band, artificiallyformed along a surface of a substrate of a silicon optoelectronic deviceaccording to the present invention;

FIG. 14 depicts a microdefect pattern self-assembled along a surface ofa substrate, like in U.S. patent application Ser. No. 10/122,421;

FIG. 15 is a graph showing simulation results of light emissioncharacteristics of two silicon optoelectronic devices havingrespectively periodic triangular and trapezoidal microdefects formedalong the surfaces of substrates as shown in FIGS. 10 and 11, and amicrodefect-free silicon optoelectronic device, i.e., a siliconoptoelectronic device having a planar substrate surface;

FIG. 16 is a schematic plan view of an image input and/or outputapparatus according to a first embodiment of the present invention;

FIG. 17 is a schematic exploded perspective view of an image inputand/or output apparatus according to a second embodiment of the presentinvention;

FIG. 18 is a schematic plan view of the structure of a color filter inthe image input and/or output apparatus shown in FIG. 17;

FIG. 19 is a schematic plan view of an image input and/or outputapparatus according to a third embodiment of the present invention;

FIG. 20 is a schematic view of an embodiment of an image input and/oroutput apparatus according to the present invention in an aspect ofimage input and output;

FIGS. 21A and 21B are schematic views of another embodiment of an imageinput and/or output apparatus according to the present invention in anaspect of image input and output; and

FIG. 22 is a schematic view of a digital television using an image inputand/or output apparatus according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present applicant has suggested a silicon optoelectronic devicehaving an ultra-shallow doping region to form a quantum structure in ap-n junction of a silicon-based substrate under U.S. patent applicationSer. No. 10/122,421 filed on Apr. 16, 2002, titled “siliconoptoelectronic device and light-emitting apparatus using the same”. Inthe silicon optoelectronic device disclosed in the above application,surface flections, i.e., microdefects of a desired size and period thatserve to increase wavelength selectivity are self-assembled under aspecific oxidation condition and a specific diffusion process. For thisreason, uniform formation and reproduction of the surface flections arevery difficult.

As mentioned in the above application, the wavelength of a siliconoptoelectronic device having light reception and/or emissioncharacteristics by a quantum structure formed by an ultra-shallowdiffusion process is determined by microflections formed along a surfaceof the silicon optoelectronic device. In this regard, in order to selecta desired wavelength band, the microflections having a desired size mustbe arrayed in a desired period.

A silicon optoelectronic device according to the present invention ischaracterized in that a desired flection structure, i.e., a microdefectpattern is artificially formed by controlling the surface shape of thesilicon optoelectronic device to thereby increase the selectivity of adesired wavelength band, unlike in the above application in whichflections are self-assembled along a surface of a silicon optoelectronicdevice during the fabrication of the silicon optoelectronic device. Ofcourse, a silicon optoelectronic device according to the presentinvention can both emit and receive light, like the siliconoptoelectronic device disclosed in the above application.

A selected wavelength band and the degree of amplification aredetermined by the sizes and shapes of surface flections, and the gapbetween the surface flections, i.e., the period of the surfaceflections. In this regard, when the pattern of the surface protrusionsis optimized according to the applications of silicon optoelectronicdevices, light-emitting efficiency can be increased. Further, only lightof a specific wavelength band can be efficiently emitted and/orreceived.

FIGS. 3 through 6 show processes of manufacturing a siliconoptoelectronic device according to an embodiment of the presentinvention.

Referring to FIG. 3, first, an n- or p-type silicon-based substrate 1 isprepared. The substrate 1 is made of a predetermined semiconductormaterial containing silicon (Si), for example, Si, SiC, or diamond, andis doped to an n-type.

Next, a microdefect pattern 7 is artificially formed to a desired size,shape, and period along a surface of the substrate 1 by etching, asshown in FIGS. 4A through 4E. Openings 5 have been exaggerated in FIG.4B and the microdefect pattern 7 has been exaggerated in FIGS. 4Cthrough 4E and FIG. 12 as will be described later.

FIGS. 4A through 4E show an example of a method of forming surfaceflections to a desired shape and size.

In order to artificially form the microdefect pattern 7, first, a masklayer 3 is formed on a surface of the prepared substrate 1, as shown inFIG. 4A. The mask layer 3 is formed by coating a photoresist layer of adesired thickness on the surface of the substrate 1, followed by hardbaking.

Next, the openings 5 of a desired size and period are formed in the masklayer 3, as shown in FIG. 4B.

The openings 5 may be formed using an atomic force microscopy (AFM)probe.

The AFM is a type of a scanning probe microscopy (SPM) that can obtainstereoscopic information about the surface structure of a matter and canrelatively easily obtain information about atomic arrangements ofsurfaces even to angstrom (□) levels. The AFM can obtainthree-dimensional surface information by scanning a matter surface intwo-dimensions using a small and sharp probe called as a tip. The AFMuses a principle of imaging a spatial distribution of the height of aprobe while keeping constant a repulsive force between the probe and thesample surface, i.e., a distance between the probe and the samplesurface. Since a repulsive force is a force that acts generally on allmatters, the AFM can also be applied in an insulator which does nottransmit electricity.

When the AFM is used in the formation of the openings 5 in the masklayer 3 instead of surface information detection, the openings 5 of adesired size and period can be patterned.

In the formation of the openings 5 in the mask layer 3, an AFM having asingle probe or an AFM having multi-probe being a one-dimensional ortwo-dimensional array of a plurality of probes may be used.

FIG. 7 schematically shows a principle of forming the openings 5 in themask layer 3 using an AFM probe 11. When a tip 13 of the AFM probe 11moves in top and bottom directions at least once or more, the openings 5of a desired depth can be formed on the mask layer 3.

FIGS. 8A and 8B show various tips used in the AFM probe 11. The shapesof the openings 5 formed in the mask layer 3 vary depending on the shapeof the tip.

A multi-probe cantilever having a one-dimensional array of a pluralityof AFM probes 11 or a multi-probe cantilever having a two-dimensionalarray of a plurality of AFM probes 11 may be used to form the openings 5in the mask layer 3. FIG. 9 schematically shows the openings 5 formed inthe mask layer 3 using an AFM having a single probe or multi-probes.

An AFM having multi-probes can facilitate a process and can provide auniform opening pattern.

Referring again to FIG. 4B, using an AFM having a single probe ormulti-probes can form the openings 5 of a desired depth, shape, andperiod in the mask layer 3.

In order to obtain a silicon optoelectronic device of a singlewavelength band, the openings 5 are formed to a single period. In thiscase, the silicon optoelectronic device emits and/or receives only lightof a specific wavelength band. On the other hand, in order to obtain asilicon optoelectronic device of a plurality of wavelength bands, forexample, for white light, the openings 5 are formed to different periodscorresponding to the wavelength bands. In this case, the siliconoptoelectronic device emits and/or receives light of a plurality ofwavelength bands.

The shapes of flections formed by etching can vary according to thedepths of the openings 5 formed in the mask layer 3. FIG. 4B shows thatdeep openings 5 a are formed in some areas of the mask layer 3 andshallow openings 5 b are formed in the remaining areas of the mask layer3.

In this case, the depth, shape, and period of the openings 5 areselected according to a desired wavelength.

After forming the openings 5 of a desired depth, shape, and period inthe mask layer 3 as described above, when etching is carried out asshown in FIGS. 4C and 4D, a micro-flection pattern, i.e., themicrodefect pattern 7 is formed. Preferably, a dry etching process isused. A wet etching process may also be used.

Thin photoresist areas, i.e., the portions formed the deep openings 5 aare etched and opened faster than thick photoresist areas, i.e., theportions formed the shallow openings 5 b. Exposed portions of thesubstrate 1 corresponding to the openings are also etched during theetching, thereby creating a flectional surface of the substrate 1.Therefore, the microdefect pattern 7 is artificially formed along thesurface of the substrate 1.

In this case, the surface of the substrate 1 corresponding to the deepopenings 5 a of the mask layer 3 is etched deeply and widely, therebyforming flections having a triangular peak shape (similar to a cone or apolygonal pyramid as viewed in three-dimensions). On the other hand, thesurface of the substrate 1 corresponding to the shallow openings 5 b ofthe mask layer 3 is etched shallowly and narrowly, thereby formingflections having a trapezoidal peak shape (similar to a truncated coneor a truncated polygonal pyramid as viewed in three-dimensions).

FIG. 10 is a schematic view of flections, i.e., a microdefect pattern 7′having a triangular peak shape formed along a surface of the substrate1, as viewed in two dimensions. FIG. 11 is a schematic view of amicrodefect pattern 7″ having a trapezoidal peak shape formed along asurface of the substrate 1, as viewed in two dimensions.

As described above, by varying the depths of the openings 5 formed inthe mask layer 3, the depth and peak shape of the flections can vary.Here, the peak shapes of the flections can vary depending on the etchingdepth, the shape, size, and/or period of the openings 5, in addition tothe depths of the openings 5 formed in the mask layer 3.

The wavelength of light emitted and/or received is determined by theperiod of the flections, i.e., the period of the microdefect pattern 7formed along the surface of the substrate 1. Light field strengthcharacteristics according to a wavelength vary according to the shapeand period of the flections.

In this regard, when the period and shape of the flections areoptimized, a desired wavelength and desired field strengthcharacteristics can be obtained.

When the mask layer 3 is removed after the above-described etching,preferably, dry etching is terminated, the surface of the substrate 1having the microdefect pattern 7 is exposed, as shown in FIG. 4E.

Since the shape, period, and depth of the microdefect pattern 7 can becontrolled during the processes as shown in FIGS. 4A through 4E, adesired wavelength can be controlled.

If the period of the microdefect pattern 7, i.e., the lengths ofmicrocavities, are long, long wavelength light is amplified. On theother hand, if the lengths of the microcavities are short, shortwavelength light is amplified.

In this regard, when the lengths of the microcavities inducing a desiredwavelength and a resonance are designed, a silicon optoelectronic devicehaving enhanced optical efficiency relative to the siliconoptoelectronic device having self-assembled microcavities disclosed inU.S. patent application Ser. No. 10/122,421 as described above can beobtained.

Further, when the lengths of the microcavities inducing a desiredwavelength and a resonance are designed so that amplification and/orabsorption of desired wavelength light is carried out, for example, on apixel-by-pixel basis on a silicon-based wafer, an array of siliconoptoelectronic devices for a high efficiency image input and/or outputapparatus as will be described later can be obtained.

Next, on the microdefect pattern 7 formed along the surface of thesubstrate 1 by the processes shown in FIGS. 4A through 4E, a controlfilm 9 having an opening 9 a is formed as shown in FIGS. 5A and 5B.While FIGS. 5A and 5B show the microdefect pattern 7 formed to a singleperiod, the microdefect patterns of different periods can be formed whenneeded as shown in the processes of FIGS. 4B through 4E, to thereby emitand/or receive light of a plurality of wavelengths.

Preferably, the control film 9 is a silicon oxide (SiO₂) film with anappropriate thickness so that a doping region is formed to anultra-shallow doping depth. For example, the control film 9 can bepatterned in such a way that a SiO₂ film is formed on the microdefectpattern 7 as shown in FIG. 5A and then etched by a photolithographyprocess to form the opening 9 a for a diffusion process. The controlfilm thus patterned has a mask structure as shown in FIG. 5B.

Preferably, the SiO₂ film is formed by a dry oxidation process. Sincethe dry oxidation process is carried out for a long duration, thesubstrate 1 can have good surface flections.

The control film 9 acts as a mask in the formation of the doping regionso that the doping region can be formed to an ultra-shallow depth. Thecontrol film 9 may be removed after the formation of the doping region.

Next, the doping region 10 is formed to an ultra-shallow depth in thesurface of the substrate 1 having the microdefect pattern 7 in such away that a predetermined dopant of the opposite type to the substrate 1is injected into the substrate 1 through the opening 9 a of the controlfilm 9, as shown in FIG. 6.

When a predetermined dopant such as boron and phosphorus is injectedinto the substrate 1 through the opening 9 a of the control film 9 by anon-equilibrium diffusion process (for example), the doping region 10 isultra-shallowly doped with the opposite type to the substrate 1, forexample, a p+ type, along the texture of the microdefect pattern 7. Atthe same time, a p-n junction 8 having a quantum structure is formed atan interface between the doping region 10 and the substrate 1.

Although a non-equilibrium diffusion process is used herein for theformation of the ultra-shallow doping region 10, another processes suchas an implantation process can also be used provided that the dopingregion 10 can be formed to a desired shallow depth.

The substrate 1 may be doped to a p type and the doping region 10 may bedoped to an n+ type.

As described above, when a doping process is controlled so that thedoping region 10 can be formed to an ultra-shallow depth, a quantumstructure comprised of at least one of quantum wells, quantum dots, andquantum wires is formed at an interface between the doping region 10 andsubstrate 1, i.e., the p-n junction 8. Therefore, the quantumconfinement effect occurs at the p-n junction 8, thereby expressing thephotoelectric conversion effect.

Quantum wells are mostly formed at the p-n junction 8. Quantum dots orquantum wires may also be formed. A composite structure comprised of twoor more types of quantum wells, quantum dots, and quantum wires may alsobe formed at the p-n junction 8. Since the quantum structure formed atthe p-n junction 8 is disclosed in the above-described patentapplication, the detailed descriptions thereof will be omitted.

At the quantum structure of the p-n junction 8, doping portions ofopposite conductivity types alternate with each other. Wells andbarriers may be about 2 and 3 nm thick, respectively.

Such ultra-shallow doping for forming the quantum structure at the p-njunction 8 can be accomplished by optimally controlling the thickness ofthe control film 9 and the conditions of a diffusion process.

The thickness of a diffusion profile can be adjusted to 10-20 nm (forexample) by an appropriate diffusion temperature and a deformedpotential due to the microdefect pattern 7 formed along the surface ofthe substrate 1 during a diffusion process. The quantum structure iscreated by the ultra-shallow diffusion profile thus formed.

As well known in the field of the diffusion technology, when a SiO₂ filmis thicker than an appropriate thickness (e.g. several thousandangstroms) or a diffusion temperature is low, vacancies mainly affectdiffusion, thereby causing a deep diffusion. On the other hand, when aSiO₂ film is thinner than an appropriate thickness or the diffusiontemperature is low, Si self-interstitials mainly affect diffusion,thereby causing a deep diffusion. Therefore, when a SiO₂ film is formedto an appropriate thickness in which the Si self-interstitials and thevacancies are generated at a similar ratio, combination of the Siself-interstitials and the vacancies retards dopant diffusion. As aresult, an ultra-shallow doping is accomplished. The physical propertiesof the vacancies and the self-interstitials as used herein are welldisclosed in the field of the diffusion technology, and thus, thedetailed descriptions thereof will be omitted.

When the control film 9 is formed with a plurality of openings 9 a onthe microdefect pattern 7 and a plurality of doping regions 10 areformed through the openings 9 a, an array of a plurality of siliconoptoelectronic devices can be obtained.

When the microdefect pattern 7 is formed to different periods, thecontrol film 9 is formed with a plurality of openings 9 a correspondingto the periods, and a plurality of doping regions 10 a are formedthrough the openings 9 a, an array of a plurality of siliconoptoelectronic devices that emit and/or receive light of a plurality ofwavelengths can be obtained.

Further, when an electrode pattern is formed on the substrate 1 to beelectrically connected to the doping region 10 thus formed, a siliconoptoelectronic device 20 shown in FIG. 12 is obtained.

Referring to FIG. 12, a first electrode 15 is formed at the same surfaceof the substrate 1 as at which the doping region 10 is formed and asecond electrode 17 is formed on the lower surface of the substrate 1.The same reference numerals as in the above-described drawings indicatesubstantially the same constitutional elements. FIG. 12 shows that thefirst electrode 15 made of an opaque metal is formed in such a way to bein contact with external sides of the doping region 10. The firstelectrode 15 may also be made of a transparent electrode material suchas indium tin oxide (ITO). In this case, the first electrode 15 may beformed on the entire surface of the doping region 10.

As shown in FIG. 12, the substrate 1 surface of the siliconoptoelectronic device 20 according to the present invention has adesired flection structure, i.e., the microdefect pattern 7 formed bythe above-described processes. The microdefect pattern 7 may be formedto various shapes, in addition to a triangle (see FIG. 10) or atrapezoid (see FIG. 11).

The silicon optoelectronic device 20 according to the present inventionas shown in FIG. 12 can be used as a light-emitting and/or receivingdevice since the p-n junction 8 between the doping region 10 and thesubstrate 1 has a quantum structure at which the creation andrecombination of electrons-holes pairs occur.

That is, the silicon optoelectronic device 20 functions as alight-emitting device as follows. For example, if an electric power(voltage or current) is applied across the first and second electrodes15 and 17, carriers, i.e., electrons and holes, are injected into thequantum wells of the p-n junction 8 and recombined (annihilated) at asubband energy level of the quantum wells. In this case, electroluminescence (EL) occurs at various wavelengths according to therecombination state of carriers, and only light of a specific wavelengthband is amplified and output according to the period of the microdefectpattern 7. The quantity of light generated varies depending on themagnitude of the electric power (voltage or current) applied across thefirst and second electrodes 15 and 17.

The silicon optoelectronic device 20 also functions as a light-receivingdevice as follows. When only light of a specific wavelength bandaccording to the period of the microdefect pattern 7 artificially formedis incident and photons are absorbed in the p-n junction 8 having thequantum wells, electrons and holes are excited at a subband energy levelof the quantum wells formed at the p-n junction 8. Therefore, when anexternal circuit, for example, a load resistance (not shown) isconnected to an output terminal, current proportional to the quantity oflight received is output.

The silicon optoelectronic device 20 having the ultra-shallow dopingregion 10 as described above has high quantum efficiency since thequantum confinement effect occurs due to local variations in potentialof charge distribution at the p-n junction 8 and a subband energy levelis made in the quantum wells.

As shown in FIG. 13, according to the present invention, when themicrodefect pattern 7 having desired periods, for example, periodsT_(R), T_(G), and T_(B) corresponding to a red light wavelength band R,a green light wavelength band G, and a blue light wavelength band B,respectively, are artificially formed along the surface of the substrate1, the silicon optoelectronic device 20 capable of emitting and/orreceiving light of desired specific wavelength bands, for example, red,green, and blue light can be obtained.

On the other hand, like in U.S. patent application Ser. No. 10/122,421,in the case of microdefects 17 self-assembled along a surface of asubstrate, the microdefects have an irregular pattern, as shown in FIG.14, thereby lowering the selectivity of wavelength bands.

FIG. 15 is a graph showing simulation results of light emissioncharacteristics of two silicon optoelectronic devices havingrespectively periodic triangular (‘Triangle’) and trapezoidal(‘Trapezoid’) microdefects 7′ and 7″ formed along the surfaces ofsubstrates 1 as shown in FIGS. 10 and 11, and a microdefect-free siliconoptoelectronic device, i.e., a silicon optoelectronic device having aplane substrate surface (‘Plane’). Here, a silicon optoelectronic devicehaving self-assembled irregular microdefects of various sizes exhibitssimilar light emission characteristics to the silicon optoelectronicdevice having the plane substrate surface.

In FIG. 15, a horizontal axis represents a generated light wavelength innanometers (nm) and a vertical axis represents field strength of thegenerated light in an arbitrary unit.

As shown in FIG. 15, silicon optoelectronic devices having themicrodefect pattern 7 artificially formed according to the presentinvention exhibit improved wavelength band selectivity andlight-emitting efficiency, relative to otherwise silicon optoelectronicdevices.

That is, as shown in FIG. 15, when microdefects artificially formedalong the surface of a substrate have a specific shape and period,light-emitting efficiency of a specific wavelength band is greatlyenhanced. If the period and size of the microdefects are changed, a peak(i.e., position of a wavelength band (Δλ) that exhibits light-emittingefficiency exceeding a predetermined intensity) can shift and the sizeof the peak can also vary.

FIG. 15 shows the simulation results of two-dimensional microdefectpattern models as shown in FIGS. 10 and 11. In this regard, it isunderstood that a three-dimensional microdefect pattern can provide moreenhanced wavelength band selectivity and light-emitting efficiency. Thatis, according to the present invention, a substrate having atwo-dimensional microdefect pattern provides an emission amplificationeffect of more than 20 to 30%, relative to a substrate having a planesurface. Therefore, it is anticipated that when the microdefect patternis optimized in three-dimensions, an emission amplification effect canbe more than doubled.

As described above, when the microdefect pattern 7 is artificiallyformed to a desired shape and period along the surface of the substrate1, good selection and amplification of a specific wavelength band can beensured.

In the silicon optoelectronic device disclosed in U.S. patentapplication Ser. No. 10/122,421 as described above, the sizes ofmicrodefects that determine wavelength selectivity cannot be easilycontrolled since the microdefects are self-assembled. In the case ofmicrocavities spontaneously formed like in U.S. patent application Ser.No. 10/122,421, i.e., self-assembled microcavities, variousmicrocavities of different wavelengths are easily mixed, and thus, it isdifficult to settle the specific process conditions for wavelengthselection.

However, according to the present invention, desired microcavities canbe artificially formed at desired positions using very simple processesas shown in FIGS. 4A through 4E. Therefore, silicon optoelectronicdevices of specific wavelength bands can be easily obtained, therebyimproving uniformity and reproducibility.

In particular, according to the present invention, since regularmicrocavities can be formed along the surface of the siliconoptoelectronic device 20, only light of a specific wavelength band canbe filtered. Furthermore, such regular microcavities can lead toamplification of light of a specific wavelength band and attenuation ofan unwanted wavelength band, unlike a conventional plane device surfaceor self-assembled irregular microdefects.

Hereinafter, as an illustrative example of apparatuses using the siliconoptoelectronic device 20 of the present invention, an image input and/oroutput apparatus will be described.

FIG. 16 is a schematic plan view of an image input and/or outputapparatus according to a first embodiment of the present invention.

Referring to FIGS. 12 and 16, an image input and/or output apparatusaccording to the first embodiment of the present invention comprises asilicon optoelectronic device panel 25 having a two-dimensional array ofsilicon optoelectronic devices 20, each of which leads to input and/oroutput of an image, formed on an n- or p-type silicon-based substrate 1.The term, “image output” as used herein indicates substantially an imagedisplay. The term, “image input” as used herein indicates substantiallygeneration of an electric image signal of an object photographed using acamera. The silicon optoelectronic devices 20 are described in theabove, and thus, the overlapped descriptions thereof will be omitted.

As described above, each of the silicon optoelectronic devices 20 can beused as a light emitting and/or receiving device of a specificwavelength band or a plurality of wavelengths bands due to the creationand recombination of electron-hole pairs by the quantum confinementeffect at the p-n junction 8 of the doping region 10.

Therefore, when a two-dimensional array of the silicon optoelectronicdevices 20 is formed on the single substrate 1 through a series ofsemiconductor manufacture processes, the silicon optoelectronic devicepanel 25 capable of inputting and/or outputting an image can beobtained.

In this case, the first and second electrodes 15 and 17 are patterned onthe substrate 11 used as a base of the silicon optoelectronic devicepanel 25 so that the input and/or output of an image can be performed ona pixel-by-pixel basis in the silicon optoelectronic device panel 25 toconvert a photographed image into an electrical image signal and/or todisplay an image in two-dimensions.

Therefore, the silicon optoelectronic device panel 25 having atwo-dimensional array of the silicon optoelectronic devices 20 can inputand/or output an image in two-dimensions.

As described above, the wavelength of light absorbed or emitted in thesilicon optoelectronic devices 20 is determined by microcavities due tothe microdefect pattern 7 artificially formed along the surface of thesubstrate 1. In this regard, when the lengths of the microcavitiesinducing a desired wavelength and a resonance are designed so thatamplification and/or absorption of desired wavelength light on a waferis carried out, for example, on a pixel-by-pixel basis, the siliconoptoelectronic device panel 25 having an array of the siliconoptoelectronic devices 20 of desired light wavelength bands can beobtained.

In this case, when the sizes of the microcavities are constant, thesilicon optoelectronic device 20 outputs and/or absorbs light of aspecific wavelength. On the other hand, when the sizes of themicrocavities are various, the silicon optoelectronic device 20 outputsand/or absorbs light of various wavelengths, for example, white light.

As mentioned above, the first and second electrodes 15 and 17 in thesilicon optoelectronic device panel 25 having a two-dimensional array ofthe silicon optoelectronic devices 20 are patterned on the silicon-basedsubstrate 1 in such a way that the input and/or output of an image canbe performed on a pixel-by-pixel basis.

In an image input and/or output apparatus according to the presentinvention, the silicon optoelectronic device panel 25 may be formed insuch a way that one of the silicon optoelectronic devices 125corresponds to one pixel P, as shown in FIG. 16.

In this case, each of the silicon optoelectronic devices 20 may bedesigned to output and/or absorb light of a single wavelength or whitelight.

When each of the silicon optoelectronic devices 20 is designed to outputand/or absorb light of a single wavelength or white light, an imageinput and/or output apparatus according to the present invention candisplay a monochromic image and/or generate an electrical monochromicimage signal of a photographed object.

Meanwhile, an image input and/or output apparatus shown in FIG. 17according to a second embodiment of the present invention comprises asilicon optoelectronic device panel 25 having a plurality of siliconoptoelectronic devices 25, each of which outputs and/or absorbs whitelight. The image input and/or output apparatus further comprises a colorfilter 30, which is installed at the front (at the side for input and/oroutput of light) of the silicon optoelectronic device panel 25 todisplay a full-color image. Therefore, the image input and/or outputapparatus can display a full-color image and/or generate an electricalfull-color image signal for a full color of a photographed object.

In this case, the color filter 30 is designed in such a way that all R,G, and B color components correspond to each pixel P, as shown in FIG.18.

The arrangement of the R, G, and B color components of the color filter30 is similar to a two-dimensional array of silicon optoelectronicdevices in a silicon optoelectronic device panel 40 (FIG. 19) accordingto another embodiment of the present invention as will be describedlater. Various changes may be made to the arrangement of the R, G, and Bcolor components in the color filter 30.

In this way, an image input and/or output apparatus including the colorfilter 30 at the front of the silicon optoelectronic device panel 25according to the second embodiment of the present invention can inputand/or output a color image. That is, this apparatus makes it possibleto convert a photographed image into an electrical color image signaland/or to display a full color image according to the electrical colorimage signal.

FIG. 19 is a schematic view of an image input and/or output imageapparatus according to a third embodiment of the present invention.

In an image input and/or output apparatus according to the thirdembodiment of the present invention, the silicon optoelectronic devicepanel 40 is designed in such a way that three or more siliconoptoelectronic devices correspond to each pixel P. FIG. 19 shows anexample of the silicon optoelectronic device panel 40 having threesilicon optoelectronic devices 20R, 20G, and 20B per each pixel P.

In this case, the three silicon optoelectronic devices 20R, 20G, and 20Bcorresponding to each pixel P output and/or absorb red light R, greenlight G, and blue light B (for example), respectively and then convertthe detected color light into respective electrical color image signals.The three silicon optoelectronic devices 20R, 20G, and 20B havemicrodefect patterns of different periods corresponding to specificwavelength bands, for example, red light R, green light G, and bluelight B. The arrangements and used materials of other constitutionalelements of the three silicon optoelectronic devices 20R, 20G, and 20Bare the same as those of the silicon optoelectronic devices 20 accordingto the present invention described above.

The silicon optoelectronic device panel 40 according to the thirdembodiment of the present invention as shown in FIG. 19 can display acolor image without using a separate color filter.

The color filter 30 as shown in FIG. 18 may be positioned at the frontof the silicon optoelectronic device panel 40 in order to represent moredistinct color image.

Various changes may be made with respect to color arrangement of thethree silicon optoelectronic devices 20R, 20G, and 20B outputting and/orabsorbing light of three wavelengths per each pixel and/or arrangementof the R, G, B components in the color filter 30.

As described above, various changes may be made with respect to inputand/or output of an image in an image input and/or output apparatusaccording to the present invention that can input and/or output amonochromic or color image. These changes can be accomplished by varyingthe structure of a circuit controlling the input and/or output of animage.

That is, an image input and/or output apparatus according to the presentinvention can input and output an image using image input pixels andimage output pixels that are alternately arranged, as shown in FIG. 20.In FIG. 20, pixels represented by oblique lines are image input pixels,i.e., pixels in which the silicon optoelectronic devices 20 according tothe present invention are used as light-receiving devices. On the otherhand, pixels represented by empty squares are image output pixels, i.e.,pixels in which the silicon optoelectronic devices 20 according to thepresent invention are used as light-emitting devices.

As shown in FIG. 20, an image input and/or output apparatus according tothe present invention may be formed in such a way that some of thesilicon optoelectronic devices 20 of the silicon optoelectronic devicepanel 25 or 40 input an image and the others of the siliconoptoelectronic devices output an image.

The image input pixels and the image output pixels may have variousarrangements. For example, pixels positioned at predetermined areas ofthe silicon optoelectronic device panel 25 or 40 can be used as theimage input pixels and the other pixels can be used as the image outputpixels.

Since the silicon optoelectronic devices 20 can be used aslight-emitting and/or receiving devices, the image input pixels and theimage output pixels can be switched when needed in an image input and/oroutput apparatus according to the present invention in which the inputand output of an image are carried out by different siliconoptoelectronic devices 20 as shown in FIG. 20. The number of the imageinput pixels and the image output pixels may also be altered. Suchalteration can be accomplished by appropriately designing the drivingand/or control circuits and algorism of an image input and/or outputapparatus according to the present invention.

An image input and/or output apparatus according to the presentinvention may also be formed in such a way that the input and output ofan image can be carried out by the same silicon optoelectronic devicewith a time difference, as shown in FIGS. 21A and 21B. FIG. 21A shows animage input state of the silicon optoelectronic device panel 25 or 40 ofan image input and/or output apparatus according to the presentinvention and FIG. 21B shows an image output state of the siliconoptoelectronic device panel 25 or 40 of an image input and/or outputapparatus according to the present invention.

Each pixel of the silicon optoelectronic device panel 25 or 40 shown inFIGS. 20, 21A, and 21B may correspond to one silicon optoelectronicdevice 20 (see FIGS. 16 and 17) or to three or more siliconoptoelectronic devices 20R, 20B, and 20C (see FIG. 19).

While an image input and/or output apparatus according to the presentinvention has been particularly shown and described with reference toexemplary embodiments thereof, various changes thereof may be madetherein without departing from the scope of the present invention.

Since an image input and/or output apparatus according to the presentinvention as described above can directly input optical information in ascreen, it can be used in equipment requiring interactive visualcommunications and/or bi-directional information transmission such ascomputer monitors, televisions, in particular, digital televisions, andhandheld terminals.

In this case, since an image input and/or output apparatus according tothe present invention allow for input and output of an image in a singlepanel, using a separate camera is eliminated upon visual communications.

Handheld terminals may be various types of portable communicationequipment such as mobile phones and personal digital assistants (PDAs).

Furthermore, an image input and/or output apparatus according to thepresent invention can input and output an image in a single panel, andthus, a full face of an operator can be photographed and transmitted.Therefore, vividness in visual communications is enhanced.

Up until now, the present invention has been described with a view to animage input and/or output apparatus comprising a single siliconoptoelectronic device panel having a two-dimensional array of siliconoptoelectronic devices, but is not limited thereto. That is, an imageinput and/or output apparatus according to the present invention maycomprise combinations of a plurality of silicon optoelectronic devicepanels to provide a larger screen.

FIG. 22 shows a digital television using an image input and/or outputapparatus according to the present invention.

Referring to FIG. 22, an image input and/or output apparatus accordingto the present invention can be used in a digital television 50 whichallows for input of information into a screen 51 and selection of a menuusing an optical wireless remote controller 55. The optical wirelessremote controller 55 can irradiate light only in a specific region likean optical pointer. When an optical signal is irradiated onto a specificregion within the screen 51, for example, a predetermined menu 53, fromthe optical wireless remote controller 55, a silicon optoelectronicdevice, which is positioned in the specific region and serves as alight-receiving device, receives the optical signal. According to thereceived optical signal, changing channels of the digital television 50or working on the Internet is possible.

In addition, an image input and/or output apparatus of the presentinvention can be applied in various equipments requiring bidirectionalinformation transmission.

As is apparent from the above description, a silicon optoelectronicdevice according to the present invention has superior light-emittingefficiency to a conventional light-emitting device using silicon, can beused as at least one of a light-emitting device and a light-receivingdevice, and has high wavelength selectivity.

In addition, a silicon optoelectronic device panel having atwo-dimensional array of silicon optoelectronic devices according to thepresent invention can be applied in an image input and/or outputapparatus capable of directly displaying an image and/or inputtingoptical information in a screen.

In particular, since a silicon optoelectronic device according to thepresent invention can be used as both of a light-emitting device and alight-receiving device, an image input and output apparatus forbidirectional information transmission that can display an image andinput an image or optical information in a single panel can be produced.

Using an image input and/or output apparatus according to the presentinvention eliminates use of a separate camera upon visual communication,thereby enhancing vividness in visual communications. When an imageinput and/or output apparatus according to the present invention is usedin a digital television, direct selection of a menu using an opticalwireless remote controller is possible.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, it will be understoodby those of ordinary skill in the art that various changes in form anddetails may be made therein without departing from the spirit and scopeof the present invention as defined by the following claims.

1-12. (canceled)
 13. A silicon optoelectronic device manufactured by themethod of manufacturing a silicon optoelectronic device comprising:preparing an n- or p-type silicon-based substrate; forming a microdefectpattern along a surface of the substrate by etching; forming a controlfilm with an opening on the microdefect pattern; and forming a dopingregion on the surface of the substrate having the microdefect pattern insuch a way that a predetermined dopant of the opposite type to thesubstrate is injected onto the substrate through the opening of thecontrol film to be doped to a depth so that a photoelectric conversioneffect leading to light emission and/or reception by quantum confinementeffect in a p-n junction occurs.
 14. The silicon optoelectronic deviceaccording to claim 13, wherein the microdefect pattern has a periodcorresponding to the wavelength of light emitted and/or received. 15.The silicon optoelectronic device according to claim 14, wherein themicrodefect pattern is formed to a single period to emit and/or receivelight of a single wavelength.
 16. The silicon optoelectronic deviceaccording to claim 14, wherein when the microdefect pattern is formed toa plurality of microdefect pattern regions having different periods, thecontrol film is formed with a plurality of openings corresponding to theperiods, and a plurality of doping regions are formed through theopenings, an array of a plurality of silicon optoelectronic devices thatemit and/or receive light of a plurality of wavelengths is formed. 17.The silicon optoelectronic device according to claim 13, wherein thecontrol film is selectively removed after the formation of the dopingregion.
 18. A silicon optoelectronic device manufactured by the methodaccording to claim 13, wherein forming the microdefect patterncomprises: forming a mask layer on the surface of the substrate; formingopenings of a desired size and period in the mask layer; etching thesurface of the substrate corresponding to the openings of the mask layerto form the microdefect pattern along the surface of the substrate; andremoving the mask layer.
 19. The silicon optoelectronic device accordingto claim 18, wherein the microdefect pattern has a period correspondingto the wavelength of light emitted and/or received.
 20. The siliconoptoelectronic device according to claim 19, wherein the microdefectpattern is formed to a single period to emit and/or receive light of asingle wavelength.
 21. The silicon optoelectronic device according toclaim 19, wherein when the microdefect pattern is formed to a pluralityof microdefect pattern regions having different periods, the controlfilm is formed with a plurality of openings corresponding to theperiods, and a plurality of doping regions are formed through theopenings, an array of a plurality of silicon optoelectronic devices thatemit and/or receive light of a plurality of wavelengths is formed. 22.The silicon optoelectronic device according to claim 18, wherein thecontrol film is selectively removed after the formation of the dopingregion.
 23. A silicon optoelectronic device manufactured by the methodaccording to claim 13, further comprising forming first and secondelectrodes on the substrate to be electrically connected to the dopingregion.
 24. The silicon optoelectronic device according to claim 23,wherein the microdefect pattern has a period corresponding to thewavelength of light emitted and/or received.
 25. The siliconoptoelectronic device according to claim 24, wherein the microdefectpattern is formed to a single period to emit and/or receive light of asingle wavelength.
 26. The silicon optoelectronic device according toclaim 24, wherein when the microdefect pattern is formed to a pluralityof mirodefect pattern regions having different periods, the control filmis formed with a plurality of openings corresponding to the periods, anda plurality of doping regions are formed through the openings, an arrayof a plurality of silicon optoelectronic devices that emit and/orreceive light of a plurality of wavelengths is formed.
 27. The siliconoptoelectronic device according to claim 23, wherein the control film isselectively removed after the formation of the doping region.
 28. Animage input and/or output apparatus comprising a silicon optoelectronicdevice panel having a two-dimensional array of silicon optoelectronicdevices, each of which inputs and/or outputs an image, formed on an n-or p-type silicon-based substrate, each of the silicon optoelectronicdevices comprising: a microdefect pattern formed along a surface of thesubstrate by etching; and a doping region formed on the surface of thesubstrate having the microdefect pattern using a predetermined dopant ofthe opposite type to the substrate to be doped to a depth so that aphotoelectric conversion effect leading to light emission and/orreception by quantum confinement effect in a p-n junction occurs. 29.The image input and/or output apparatus according to claim 28, whereinthe microdefect pattern is formed by forming a mask layer on the surfaceof the substrate; forming openings of a desired size and period in themask layer; and etching the surface of the substrate corresponding tothe openings of the mask layer.
 30. The image input and/or outputapparatus according to claim 28, wherein the microdefect pattern has aperiod corresponding to the wavelength of light emitted and/or received.31. The image input and/or output apparatus according to claim 28,wherein when both input and output of an image are possible, some of thesilicon optoelectronic devices input an image and the others of thesilicon optoelectronic devices output an image.
 32. The image inputand/or output apparatus according to claim 28, wherein when both inputand output of an image are possible, each of the silicon optoelectronicdevices inputs and outputs an image.
 33. The image input and/or outputapparatus according to claim 28, wherein electrodes are patterned on thesubstrate to carry out the input and/or output of an image from thesilicon optoelectronic device panel on a pixel-by-pixel basis.
 34. Theimage input and/or output apparatus according to claim 28, wherein thesilicon optoelectronic device panel comprises three or more of thesilicon optoelectronic devices per each pixel.
 35. The image inputand/or output apparatus according to claim 34, wherein the three or moreof the silicon optoelectronic devices corresponding to each pixel havemicrodefect patterns of different periods and emit and/or receive lightof different wavelengths to represent a color image.